This invention relates to periodic cleaning of heat exchangers and, more particularly, to a structure for supporting, transporting and subsequent cleaning of a tube bundle after removal of the bundle from an oil cooler shell.
Turbine generators include parts such as bearings which must be lubricated and cooled during operation of the generator. Oil has been used as the lubricating and cooling medium. As the oil moves across the bearings, the oil heats up and must itself be cooled. For this purpose, the oil is recirculated through a cooler shell which houses a bundle of over a thousand elongated tubes through which cooling water is passed. The oil repeatedly passes across the tubes, cools, and returns to the turbine generator.
The tube bundles must be periodically removed from the cooler shells and cleaned to ensure proper operation of the bundles and oil system cleanliness. Conventionally, a tube bundle removed from a cooler shell might remain vertical and be cleaned within a curtain structure adjacent the cooler shell. However, this method does not allow full cleaning of the tube bundle and erecting the temporary curtain structure is time consuming.
Alternatively, the vertical bundle is removed via an overhead crane and placed horizontally in a chemical cleaning vat. Use of the vat eliminates the need to erect the curtain structure. However, the tube bundles are not inherently strong structures. They are not made to be simply flipped from the vertical to the horizontal. For example, after the tube bundles are manufactured horizontally, they are inserted in the cooler shell and the shell is flipped to the vertical. Thus, the tube bundle would bend or bow if moved from the vertical to the horizontal position. Of course, overall heat exchanger operational costs and power plant down-time increases, while the bent bundles are being repaired/replaced.
Finally, due to the relative bulkiness of the bundle, it is difficult to clean the tube bundle in the conventional vat.